The present invention relates to a feeder of sheet-like photo-sensitive materials to a drum in an electrophotographic printer. The feeding process is performed by winding the sheet-like photo-sensitive materials on the drum material surface and rotating the thus arranged drum.
In a conventional construction as shown in FIG. 5, after discharging the photosensitive material 7, which is no longer useable, from the peripheral surface of the drum I, the drum 1 is stopped. After opening a front end clamp 2 and making a clamping preparation, the unused photo-sensitive material 7 is fed out by means of the roller 6 from the tray 5 along the guide 4 to the front end clamp 2. After the front end of the photo-sensitive material 7 has been clamped by front end clamp 2, the drum 1 is rotated counterclockwise by an unillustrated drum driving means thereby winding the material 7 thereon. Subsequently, the drum 1 is stopped to clamp the rear end of the material 7, at which time the rear end clamp 3 clamps the rear end of the material 7.
In the prior art device depicted in FIG. 5, there exists a high probability that a sheet of the sheet-like photo-sensitive material 7 will be superposed on another sheet or obliquely transferred when being fed from the tray 5. This causes an error in the winding process. In addition a sheet of the photosensitive material fed out for winding which is brought into slide-contact with another sheet of photo-sensitive material stored in the tray 5 will probably be damaged. This leads to a decline in the quality of printed materials. Because the photo-sensitive material 7 assumes a tabular configuration a relatively large space is required for accommodating the tray 5, resulting in an increase in size. Furthermore, it is inconvenient to have the sheet-like photosensitive materials sit around when loading the photo-sensitive materials.
FIG. 6 shows a rolled photo-sensitive material in association with another conventional technique which solves the following problems inherent in the prior art of FIG. 5: (1) the photo-sensitive materials are superposed on each other and obliquely transferred; (2) damage is caused to the surfaces of the materials; (3) a relatively large space is needed for accommodation; and (4) it is inconvenient to have the photosensitive materials sit around. When winding the photosensitive materials on the drum by the conventional technique depicted in FIG. 6, there is an added step of cutting the rolled photosensitive material 7 to a required length with the cutter 9 prior to the step of clamping the rear end thereof by the conventional technique shown in FIG. 5.
Although the conventional technique of FIG. 6 is capable of eliminating the defects incidental to the prior art shown in FIG. 5, it involves the use of the cutter 9 for cutting the rolled photo-sensitive material to the required length. This arrangement increases the production costs of the feeder. Organic photosensitive material well known as an inexpensive material to form photo-sensitive sheets 7 tends to invariably cause deterioration in some portions when forming this material into a lengthy sheet. In the rolled photo-sensitive material, it is impossible to remove the deteriorated portions by cutting them off, and such portions are wound on the drum, thereby causing a decline in quality of the printed material. When obtaining the printed materials with no deteriorated portion, there must be a limit to the length of a sheet. In addition, the yield is also decreased.